Mission critical industries (e.g., electrical utilities, oil and gas industries etc.) have assets deployed in remote areas often not well covered by public wire line and wireless telecommunication networks. Moreover, even when public telecommunication services are available, mission critical industries are reluctant to use these services and prefer to operate their own private wireless networks. These networks typically have got their own towers with a serving area that extends up to 20 miles radius.
Traditionally, mission critical industries have built and operated voice centric Private Land Mobile Radio (PLMR) systems making it difficult to support emerging mission critical mobile and fixed data applications such as remote data base access, for example. These systems have several drawbacks, as follows:                Communication in PLMR systems is done over narrowband PLMR channels. A PLMR channel width of 25 KHz is typically being used, but the FCC regulations have mandated the narrow banding of certain frequencies, reducing channel sizes from 25 KHz to 12.5 KHz in order to double the number of available PLMR channels. The FCC is considering a further decrease in PLMR channel width to 6.25 KHz. As a result, while PLMR channels can support excellent voice quality, data communication is very slow.        Most PLMR systems are circuit switched systems. As such, they are not efficient for data communication. Research with real customer data reveals that channel voice occupancy is typically very low.        
Several solutions are currently used by mission critical industries to deliver data services:                Public wireless networks: These networks typically lack coverage across the PLMR user's serving area. Public wireless networks have two additional challenges with respect to serving mission critical industries.        Given their commitment to serve the general public, they cannot prioritize, mission critical customers over general public customers. The bandwidth available to the mission critical customer will therefore depend on the general public usage. As a result, these systems are not considered mission critical by the mission critical customers.        The mission critical applications are very different from the general public typically requiring a different network design. For example, a major mission critical application is Supervisory Control and Data Acquisition (SCADA) which requires a reverse asymmetrical network (i.e., more capacity in the uplink than in the downlink) and network design that will meet tight latency requirements.        Dedicated data networks operating in unlicensed bands (900 MHz, 2.4 GHz or 5.8 GHz). These networks provide very poor coverage due to transmit power restrictions in the unlicensed bands as per FCC Part 15. In addition these systems suffer from poor receiver sensitivity due to a high noise floor generated by other users and the wide channels used (e.g., >20 MHz wide channels for WiFi based systems). The inadequate propagation because of the relatively high frequencies. (Relative to the PLMR operating frequencies). The coverage of these systems can be improved only with a costly dense node deployment. In addition, these systems are not considered robust enough for mission critical applications and are limited in their support of mobility.        Dedicated data networks operating in a nationwide licensed band (e.g. 700 MHz). This solution does supports mission critical high speed data but is very costly given that:        It is highly desirable to have an operational licensed frequency below 1 GHz which will enable the delivery of mobile broadband data services over the existing PLMR tower serving area of up to 20 miles, to avoid the need to build new towers. The cost of licensing the frequencies is very high, especially if the customer is locked to a single frequency holder.        Only few licensed frequency opportunities are available countywide while many different licensed frequency opportunities are available in limited geographies. This implies that if the equipment is designed to operate in a specific frequency, it may not have the economy of scale that is needed to bring the cost down to an acceptable level.        
There is thus a need to provide an innovative wireless system and methods to implement a mission critical high speed data solution with similar coverage to the existing PLMR voice service, which overcome the technical disadvantages of present systems.